The Maillard reaction is a complex network of reactions that alters important food attributes such as flavour, colour, nutrition value, antioxidant properties, etc. It is used by the food and flavour industry to generate flavour during processing (in-process flavour generation) and to produce process/reaction flavours. However, the control of the Maillard reaction is very challenging as the composition of the reaction products (both qualitative and quantitative) strongly depends on the reaction/processing conditions such as temperature, time, pH, water activity type of reactants etc. The control of the flavour generated during the Maillard reaction is even more challenging as the odorants are generally formed by side reactions and in very low yields. Increasing the yield of key odorants through better reaction control would significantly improve the flavour quality of thermally processed foods and/or process flavours as well as the cost efficiency of flavour precursors systems. This could be achieved by performing the reaction in several steps as opposed to one step reaction. The concept can be applied to process flavours but also to foods, petfoods and beverages. The Maillard reaction together with lipid oxidation plays an essential role in the flavour generation during food processing, and in production of process flavours. In a common approach, the process flavours are prepared by mixing of all the ingredients at once while applying the optimised reaction conditions. However the optimisation of the reaction conditions is generally an issue, because flavour compounds are typically formed by side reactions in the later stages of the Maillard reaction via a cascade of reaction steps.
Several intermediates are often necessary to form a specific flavour compound. In many cases, the optimal reaction conditions for the generation of one group of intermediates are not optimal or not even suitable for the generation of other groups of intermediates. However, formation of all intermediates is essential. If one or several intermediates are missing or are formed in low amounts, the formation of the flavour compound is limited or inhibited. This is often the case, when the Maillard reaction is performed in one step. In this approach, the reaction conditions must permit the formation of all the intermediates. As a consequence, the reaction conditions are not optimal for the generation of individual intermediates which results in low yields of flavour compounds (odorants, tastants).
Low yields of flavour compounds together with high prices of certain precursors often hinder the broader use of flavour precursors during food processing and in the production of process flavours. There is thus a need to enhance the conversion of flavour precursors into flavour active compounds to improve the cost efficiency of the precursors.